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Forest of Dean and My Forever Pond

Hoping to keep this going throughout the project, partly as a reminder to me of the journey. I have had ponds before but having recently moved to a house we’ll hopefully be in for 20+ years I’m designing and getting ready to build my dream pond.

The photos show the existing decking and goldfish pond, and also the slope on the garden. The plan being to butt up to the decking (sort of L shaped) then come down in a curve on one side missing the drain, and straight down the fence line (leaving a 3’ gap that side for access)

Had a really useful chat with Mat at Boddington Koi this afternoon so ready to get a bit more focussed on pricing up and also working out running costs.

Well got the trees down and tape up for the outline and a remeasure of course! Man with a digger is happy he can get in so that’s excellent news too. Gallonage coming out at a very reasonable number still and shape fits the garden. Need to think through the filter positioning as was going for 3 Nexus 320’s which should be more than enough for the 13,000 or so gallons given the slower throughout of those units. Was hoping to get all 3 in a line at the back but conscious of the need to have space to work around them as well as pipe work, valves and sterilisers.

Well got the trees down and tape up for the outline and a remeasure of course! Man with a digger is happy he can get in so that’s excellent news too. Gallonage coming out at a very reasonable number still and shape fits the garden. Need to think through the filter positioning as was going for 3 Nexus 320’s which should be more than enough for the 13,000 or so gallons given the slower throughout of those units. Was hoping to get all 3 in a line at the back but conscious of the need to have space to work around them as well as pipe work, valves and sterilisers.

Anyway pictures added so you can see how it’s going

Hi great to see another pond build about to start...that is a monster size pond planned! 3 Nexus units is a lot of cleaning and pipework! . Have you considered a drum and alternative bio filters too..or done all that and happy with triple Nexus’s? Good luck with it all!

Looked at drums but love how effective the biological filter properties of large moving bed works and adding the self clean units, and I can always build so a retro drum fit could happen. Oh and there’s a budget

1. Flow rate. You won't be able to turn over the whole pond volume in a reasonable time because the max flow through a Nexus is very limiting. Your pond could be nearly 60,000 litres. The absolute max flow of a 320 is 13,000 lph. This means the fastest you could ever turn over the pond would be 1.5 hours. if I were you I would plan a setup that allows for a 1 hour turnover. Also when running. at max flow Nexus Eazy sections are very bad at collecting fines.

2. Water clarity. Even with Micro K1 in the Eazy, clarity is never as good as with a drum with 60-70 micron screen. Worth visiting some ponds to see for yourself the difference before you commit to spending thousands on something that disappoints you later.

3. Maintenance- nothing quite like sitting back and watching your drum clean itself as often as needed. No more wet hands. No more standing beside boiling Nexuses while they clean. No more scooping out hundreds of litres of K1 to clean the crud that builds up beneath every few months. OMG that job is messy! No more fish poo sitting in the water for days on end before a clean cycle to remove it. Just a quick hose off of the waste chute every few weeks and maybe an annual screen cleaning if using mains water to clean screen in a hard water area. My screen has never been cleaned in 2.5 years of use.

looks good,i also agree the 3 nexus not a good idea and you set you were thinking of the auto cleaning models,for the cost you could get a drum with 3 or 4 inlets for bds and then have a bio chamber and maybe return over a shower or 2,the bio on this setup would be better than the 3 nexi,andi

with out going in to sizes and prices i would have thought for ease of maintenace is to go for a drum filter and then a goog size moving bed filter .
you have got the advatage of the lay of the land to put the drum and filter at the lower end of the pond and still get to the drain to get rid of the waste water.
the moving bed could be made out of concrete blocks and finnished with fibre glass and have a section of jap matting cartridges to rearly catch the fines.
the likly hood of finding 3 nexi second hand is very unlikley so new drum from burtons or some one at a reasonable price and make your own moving bed.
at a later stage you could put a bakki shower on if funds allow but not rearly necessary.
with out the bakki shower every thing would be out of sight apart from the lovely fish. and not hard work to look after.

Given budget constraints what would you go for instead? Can see the benefits of drums to some degree but outside of the budget for the next few years

If budget is a constraint why are you going for so large a pond? There are people on here who say their 6000g pond is too big!

If you are talking new Nexus with self clean then you are looking at similar money to a drum?? With a drum you still have the moving bed but its in a nice separate bio chamber. Seriously 2x easydrums and a JBR or block built bio chamber would give you more throughput than 3 x nexus and if you are looking at new would probably be cheaper!

1.maintenance would be much much less
2. much better fines removal
3. takes up far less space

Sound advice above.
I had a nexus large nexus and bead filter on my pond, I took it all out and replaced it with two new 220's.
The problem with the larger nexus is I couldn't get the the air ring properly, had to take it out and clean it every six month or so because of the hard water and bio film blocking it.
Since getting more into my pond again I have seem the difference the drum makes on the pond and now selling my nexus and going for drum and bio chamber and then through my Bakki.
It's expensive to do it twice like me ! Wish I had joined this forum before deciding to sort my pond!

Looked at drums but love how effective the biological filter properties of large moving bed works and adding the self clean units, and I can always build so a retro drum fit could happen. Oh and there’s a budget ��

Hi appreciate you have a budget, but 3 x self cleaning Nexus is a lot of cash, and a drum and moving bed wouldn’t be far away. I have a Nexus 320, on my 4K gallon, biologically it’s fine, but the cleaning was so regular in the summer(2x a week) plus a Easypod the same frequency on the skimmer it was a pain. As I am away also with work, it was a worry, 2 days away and the Nexus was dangerously low as needed a clean. I put a Draco drum in, and it’s great. If I had time again I’d have a separate drum without doubt.

if u consider you have 3 normal Nexus 320, cleaning once a week or maybe twice in summer you’ll also be lowering your pond water level a lot to clean and flush each one....may drop below your skimmer height...

of course we we can only offer advice, based on our experiences...at the end of the day it’s your call, be interesting to see what you decide, cheers.

Looking at AEM 100 that says it’ll handle 100m3 per hour st £3,700 which leaves £800 of budget for moving bed, interesting thought and stupidly hadn’t thought of a block built moving bed. I can remember when all filters were built of blocks too!

Has anyone got one of these units, a single unit would handle the volume needed, they seem remarkably cheap for a big drum?

AEM are the economy end of the drum range. The smallest still has a max flow of 20k which is nearly twice a nexus and retails under a grand I believe. There are some advantages going for two drums rather than 1 in that if you have problems you can keep the filtration going whilst things are sorted out.

If you want to go for a single drum a 50,000ltr max flow one like the QK50 is about as small as I would go I don't think a 35 wood be big enough and you would definitely need more bio. I would reckon on having 500lts of media initially with room in the bio chamber for another 500ltrs. The media alone will set you back £500 so needs to be included in your budget.

ive got 2 drums on mine,they are old kc-19 drums and max at 10kph but on my 5000g they work well,cost me £650 used so there are bargains out there,they both return over a 4 tier momotaro bakki with 70kg BHM,i also run a nexus 200 on my skimmer with 150lts of k1,andi